starfive-tech/linux.git/Documentation/arm64, branch rt-linux-release

Merge remote-tracking branch 'tip/sched/arm64' into for-next/core

2021-08-31T08:10:00+00:00

* tip/sched/arm64: (785 commits) Documentation: arm64: describe asymmetric 32-bit support arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 arm64: Advertise CPUs capable of running 32-bit applications in sysfs arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 arm64: Implement task_cpu_possible_mask() sched: Introduce dl_task_check_affinity() to check proposed affinity sched: Allow task CPU affinity to be restricted on asymmetric systems sched: Split the guts of sched_setaffinity() into a helper function sched: Introduce task_struct::user_cpus_ptr to track requested affinity sched: Reject CPU affinity changes based on task_cpu_possible_mask() cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 sched: Introduce task_cpu_possible_mask() to limit fallback rq selection sched: Cgroup SCHED_IDLE support sched/topology: Skip updating masks for non-online nodes Linux 5.14-rc6 lib: use PFN_PHYS() in devmem_is_allowed() ...

Merge branches 'for-next/mte', 'for-next/misc' and 'for-next/kselftest', remote-tracking branch 'arm64/for-next/perf' into for-next/core

2021-08-26T10:49:27+00:00

* arm64/for-next/perf: arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF * for-next/mte: : Miscellaneous MTE improvements. arm64/cpufeature: Optionally disable MTE via command-line arm64: kasan: mte: remove redundant mte_report_once logic arm64: kasan: mte: use a constant kernel GCR_EL1 value arm64: avoid double ISB on kernel entry arm64: mte: optimize GCR_EL1 modification on kernel entry/exit Documentation: document the preferred tag checking mode feature arm64: mte: introduce a per-CPU tag checking mode preference arm64: move preemption disablement to prctl handlers arm64: mte: change ASYNC and SYNC TCF settings into bitfields arm64: mte: rename gcr_user_excl to mte_ctrl arm64: mte: avoid TFSRE0_EL1 related operations unless in async mode * for-next/misc: : Miscellaneous updates. arm64: Do not trap PMSNEVFR_EL1 arm64: mm: fix comment typo of pud_offset_phys() arm64: signal32: Drop pointless call to sigdelsetmask() arm64/sve: Better handle failure to allocate SVE register storage arm64: Document the requirement for SCR_EL3.HCE arm64: head: avoid over-mapping in map_memory arm64/sve: Add a comment documenting the binutils needed for SVE asm arm64/sve: Add some comments for sve_save/load_state() arm64: replace in_irq() with in_hardirq() arm64: mm: Fix TLBI vs ASID rollover arm64: entry: Add SYM_CODE annotation for __bad_stack arm64: fix typo in a comment arm64: move the (z)install rules to arch/arm64/Makefile arm64/sve: Make fpsimd_bind_task_to_cpu() static arm64: unnecessary end 'return;' in void functions arm64/sme: Document boot requirements for SME arm64: use __func__ to get function name in pr_err arm64: SSBS/DIT: print SSBS and DIT bit when printing PSTATE arm64: cpufeature: Use defined macro instead of magic numbers arm64/kexec: Test page size support with new TGRAN range values * for-next/kselftest: : Kselftest additions for arm64. kselftest/arm64: signal: Add a TODO list for signal handling tests kselftest/arm64: signal: Add test case for SVE register state in signals kselftest/arm64: signal: Verify that signals can't change the SVE vector length kselftest/arm64: signal: Check SVE signal frame shows expected vector length kselftest/arm64: signal: Support signal frames with SVE register data kselftest/arm64: signal: Add SVE to the set of features we can check for kselftest/arm64: pac: Fix skipping of tests on systems without PAC kselftest/arm64: mte: Fix misleading output when skipping tests kselftest/arm64: Add a TODO list for floating point tests kselftest/arm64: Add tests for SVE vector configuration kselftest/arm64: Validate vector lengths are set in sve-probe-vls kselftest/arm64: Provide a helper binary and "library" for SVE RDVL kselftest/arm64: Ignore check_gcr_el1_cswitch binary

arm64: Document the requirement for SCR_EL3.HCE

2021-08-24T15:44:23+00:00

It is amazing that we never documented this absolutely basic requirement: if you boot the kernel at EL2, you'd better enable the HVC instruction from EL3. Really, just do it. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210812190213.2601506-6-maz@kernel.org Signed-off-by: Catalin Marinas

Documentation: arm64: describe asymmetric 32-bit support

2021-08-20T10:33:07+00:00

Document support for running 32-bit tasks on asymmetric 32-bit systems and its impact on the user ABI when enabled. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210730112443.23245-17-will@kernel.org

arm64/sme: Document boot requirements for SME

2021-08-02T10:05:24+00:00

Document our requirements for initialisation of the Scalable Matrix Extension (SME) at kernel start. While we do have the ability to handle mismatched vector lengths we will reject any late CPUs that can't support the minimum set we determine at boot so for clarity we document a requirement that all CPUs make the same vector length available. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20210720204220.22951-1-broonie@kernel.org Signed-off-by: Catalin Marinas

Documentation: document the preferred tag checking mode feature

2021-07-28T17:39:26+00:00

Document the functionality added in the previous patches. Link: https://linux-review.googlesource.com/id/I48217cc3e8b8da33abc08cbaddc11cf4360a1b86 Signed-off-by: Peter Collingbourne Reviewed-by: Catalin Marinas Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210727205300.2554659-6-pcc@google.com Acked-by: Will Deacon [catalin.marinas@arm.com: clarify that the change happens on task scheduling] Signed-off-by: Catalin Marinas

userfaultfd: do not untag user pointers

2021-07-24T00:43:28+00:00

Patch series "userfaultfd: do not untag user pointers", v5. If a user program uses userfaultfd on ranges of heap memory, it may end up passing a tagged pointer to the kernel in the range.start field of the UFFDIO_REGISTER ioctl. This can happen when using an MTE-capable allocator, or on Android if using the Tagged Pointers feature for MTE readiness [1]. When a fault subsequently occurs, the tag is stripped from the fault address returned to the application in the fault.address field of struct uffd_msg. However, from the application's perspective, the tagged address *is* the memory address, so if the application is unaware of memory tags, it may get confused by receiving an address that is, from its point of view, outside of the bounds of the allocation. We observed this behavior in the kselftest for userfaultfd [2] but other applications could have the same problem. Address this by not untagging pointers passed to the userfaultfd ioctls. Instead, let the system call fail. Also change the kselftest to use mmap so that it doesn't encounter this problem. [1] https://source.android.com/devices/tech/debug/tagged-pointers [2] tools/testing/selftests/vm/userfaultfd.c This patch (of 2): Do not untag pointers passed to the userfaultfd ioctls. Instead, let the system call fail. This will provide an early indication of problems with tag-unaware userspace code instead of letting the code get confused later, and is consistent with how we decided to handle brk/mmap/mremap in commit dcde237319e6 ("mm: Avoid creating virtual address aliases in brk()/mmap()/mremap()"), as well as being consistent with the existing tagged address ABI documentation relating to how ioctl arguments are handled. The code change is a revert of commit 7d0325749a6c ("userfaultfd: untag user pointers") plus some fixups to some additional calls to validate_range that have appeared since then. [1] https://source.android.com/devices/tech/debug/tagged-pointers [2] tools/testing/selftests/vm/userfaultfd.c Link: https://lkml.kernel.org/r/20210714195437.118982-1-pcc@google.com Link: https://lkml.kernel.org/r/20210714195437.118982-2-pcc@google.com Link: https://linux-review.googlesource.com/id/I761aa9f0344454c482b83fcfcce547db0a25501b Fixes: 63f0c6037965 ("arm64: Introduce prctl() options to control the tagged user addresses ABI") Signed-off-by: Peter Collingbourne Reviewed-by: Andrey Konovalov Reviewed-by: Catalin Marinas Cc: Alistair Delva Cc: Andrea Arcangeli Cc: Dave Martin Cc: Evgenii Stepanov Cc: Lokesh Gidra Cc: Mitch Phillips Cc: Vincenzo Frascino Cc: Will Deacon Cc: William McVicker Cc: [5.4] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64: Document requirement for access to FEAT_HCX

2021-05-25T18:05:28+00:00

v8.7 of the architecture introduced FEAT_HCX which adds an additional hypervisor configuration register HCRX_EL2. Even though Linux does not currently make use of this feature let's document that the EL3 trap for access to the register should be disabled so that we are able to make use of it in future. Signed-off-by: Mark Brown Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210512162350.20349-1-broonie@kernel.org Signed-off-by: Will Deacon

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2021-05-07T19:11:05+00:00

Pull more arm64 updates from Catalin Marinas: "A mix of fixes and clean-ups that turned up too late for the first pull request: - Restore terminal stack frame records. Their previous removal caused traces which cross secondary_start_kernel to terminate one entry too late, with a spurious "0" entry. - Fix boot warning with pseudo-NMI due to the way we manipulate the PMR register. - ACPI fixes: avoid corruption of interrupt mappings on watchdog probe failure (GTDT), prevent unregistering of GIC SGIs. - Force SPARSEMEM_VMEMMAP as the only memory model, it saves with having to test all the other combinations. - Documentation fixes and updates: tagged address ABI exceptions on brk/mmap/mremap(), event stream frequency, update booting requirements on the configuration of traps" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kernel: Update the stale comment arm64: Fix the documented event stream frequency arm64: entry: always set GIC_PRIO_PSR_I_SET during entry arm64: Explicitly document boot requirements for SVE arm64: Explicitly require that FPSIMD instructions do not trap arm64: Relax booting requirements for configuration of traps arm64: cpufeatures: use min and max arm64: stacktrace: restore terminal records arm64/vdso: Discard .note.gnu.property sections in vDSO arm64: doc: Add brk/mmap/mremap() to the Tagged Address ABI Exceptions psci: Remove unneeded semicolon ACPI: irq: Prevent unregistering of GIC SGIs ACPI: GTDT: Don't corrupt interrupt mappings on watchdow probe failure arm64: Show three registers per line arm64: remove HAVE_DEBUG_BUGVERBOSE arm64: alternative: simplify passing alt_region arm64: Force SPARSEMEM_VMEMMAP as the only memory management model arm64: vdso32: drop -no-integrated-as flag

arm64: Fix the documented event stream frequency

2021-05-05T17:34:28+00:00

It should be 10KHz, matching the ARCH_TIMER_EVT_STREAM_PERIOD_US of 100us. Note that this is only a documentation bug. Fixes: 611a7bc74ed2 ("arm64: docs: describe ELF hwcaps") Signed-off-by: Catalin Marinas Cc: Mark Rutland Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210505132845.23698-1-catalin.marinas@arm.com Signed-off-by: Catalin Marinas